Shoe last



Aug. 25, 1942. c. R. PARKER SHOE LAST Filed Feb. 1, 1940 IN VENTOR. 0/55752, P. PARA 5Q. m zmm ATTORNEYS.

Patented Aug. 25, 1942 UN [TED STATES ATENT ()FFICE SHOE LASTApplication February 1, 1940, Serial No. 316,711

4 Claims.

This invention relates to shoe lasts, and more particularly toimprovements in hollow metal lasts for the manufacture of rubberfootwear, such as boots and overshoes.

In the process of manufacturing rubber footwear, it is conventionalpractice to mount a plurality of the lasts upon a conveyor which carriesthe lasts in a predetermined path for the performance of a desiredsequence of operations, such as curing, in the manufacture of thefootwear. Hollow metal lasts have been found to be greatly superior toany other type of last for the manufacture of rubber footwear, and inprevious use thereof these lasts have been provided at their upper endfaces with a pair of holes into which studs or pins carried by theconveyor are adapted to fit for the purpose in holding the last indesired position upon the conveyor during the processing of the footwearbeing built around the last. These hollow lasts are generally formed ofsome lightweight material, such as an aluminum or magnesium alloy whichis subject to rapid wear, and consequently considerable dlfiiculty hasbeen experienced with lasts formed of these alloys by reason of the factthat the holes therein which receive the pins or studs of the conveyorare enlarged in use with resulting loose fit thereof on the conveyor pinor stud. Hence the lasts may tilt out of operative position on theconveyor.

For purposes of economy, the pins on the conveyor are so arranged thatthe adjacent sets thereof are spaced apart a distance only slightlygreater than the length of the foot portion of the last. Consequentlywhen the fitting of the last on the conveyor pin loosens to permit thelast to tilt, the tilting may result in contact of the adjacent lasts.When this is encountered during the process of making the footwear andparticularly during the process of curing thereof, the

footwear bears a mark caused by the contact of the partly formedfootwear on adjacent lasts so that said footwear is disfigured and unfitfor sale as first class merchandise. Consequently considerable loss ispossible and likely if the lasts are not firmly held upon their conveyorin proper position.

It is the primary object of my invention to provide a hollow metal lastformed of lightweight material, and so constructed and reinforced by theuse of hard metal parts as bearing surfaces engaging the conveyor pins,that the interconnection between the last and the pin will be entirelyformed of hard metal, and thus be capable of use for an indefiniteperiod without suffering wear 55 metal,

which will permit the lasts to tilt upon the conveyor.

A. further object is to provide a hollow metal last formed oflightweight material having embedded in the upper face thereof a pair ofhard metal sleeves in accurately positioned relation for the receptionof studs or pins on a conveyor.

A further object is to provide a last formed of lightweight metal withsleeves formed of hard and having knurled exterior surfaces adapted tobe embedded and firmly anchored in a wall of the soft metallast.

Other objects will be apparent from the description and appended claims.

In thedrawing:

Fig. l is a longitudinal vertical sectional view of my shoe lastillustrating the same mounted upona conveyor, and with one sleeve shownin section and the other in elevation.

Fig.2, is a transverse sectional View taken on line 2'-2 of Fig. 1.

Referring to the drawing, the numeral Ill designates a conveyor, whichis here illustrated as constituting a flexible endless chain. Theconveyor is provided at spaced points along its length with sets ofspaced upwardly extending pins or studs I I, the studs of each set beingspaced apart a predetermined dimension and the sets being spaced fromeach other a predetermined dimension. It will be understood that theconveyor I0 is mounted upon and operated by suitable supporting andoperating means (not shown) of such character that the pins or studs I Iwill always be maintained in vertical or upright position.

My improved last comprises a hollow metal member I2 of any desired shapeor form to provide a foot portion I3, heel portion l4, and leg portion15 of desired size and contour. The upper end of the leg portion l5 hasa transverse wall 16 in which an opening 11 is usually provided, saidopening I! being formed usually by the arbor mounting the core whichshapes the inner surface of the Walls of the last. The opening 11, ofcourse, also facilitates removal of the core material after the last hasbeen cast. The walls of the lasts are of substantially uniform thicknessthroughout, with the possible exception that the wall It may be slightlythicker than the remaining last walls. In no instance, however, it iscustomary to provide any wall of the last greatly exceeding A; or inchin thickness.

Within the upper wall [6 I embed in predetermined spaced exactlyparallel relation, a pair of sleeves I8 whose outer ends are preferablyeither flush with or slightly inset from the outer surface of the plateportion l6 of the last. The spacing of these sleeves must be exactly thesame from center to center as the spacing of the centers of the studs orpins H. The sleeves I8 may be of a length greater than the thickness ofthe walls l6 if desired. Whereas the last itself is formed of a softmetal, such as magnesium or aluminum alloy, the sleeves [8 arepreferably formed of steel or some other hard and substantiallynon-wearing material. The exterior faces of the sleeves l8 arepreferably knurled throughout their length, as illustrated in Fig. 1, sothat the combination of the shrinkage of the non-ferrous lightweightmaterial on the sleeves during the cast operation, together with theanchoring action of knurled outer surface, will solidly embed and securethe sleeves in desired posi- 4 tion. The interior surfaces of thesleeves I!) are preferably smooth.

It will, therefore, be seen from the above description that a solid andsubstantially nonwearing contact is provided between the last l2 and thepins ll of the conveyor. Additionally by the use of sleeves I8 of alength greater than the thickness of the last wall IS, a greater areaand extent of positioning contact is aiforded between the studs H andthe last, which assists in maintaining the last in operative positionupon the conveyor. In this way the full length of the studs ll may beutilized for accurate positioning of the last upon the conveyor withoutat the same time requiring any excessive overall thickness of the WallI6 of the last which would increase amount of the metal required andalso the weight of the last.

The problem which is solved by the use of these elongated hard metalsleeves is one of long standing and has been a source of trouble andloss to manufacturers of rubber footwear for many years. In actual testssince use of the hard metal sleeves aforesaid has been begun, it isfound that this, the instant construction, fully solves all thesedifiiculties and eliminates loss by reason of contact between adjacentlasts in the curing or other operations of the footwear While mountedupon the conveyor.

I claim:

1. A shoe last comprising a hollow cast body having a top wall, and apair of rigid preformed separate metal sleeves fixedly cast insubstantially, coplanar parallel relation in said top wall at theirouter end portions and terminating within and spaced from said body attheir inner end portions.

2. A shoe last comprising a thin-walled hollow cast body, and a pair ofpreformed open ended sleeves having roughened exterior surfaces andsubstantially smooth interior surfaces, the top wall of said body beingcast around said sleeves to permanently anchor said sleeves .in spacedsubstantially coplanar parallel relation.

3. A shoe last comprising a hollow cast body of thin wall section, and apair of rigid preformed sleeves fixedly cast at their outer end portionswithin the top wall of said body in spaced substantially coplanar andparallel relation, said sleeves being of a length greater than thethickness of said top wall and terminating within and spaced from saidbody, the inner surface of each sleeve being substantially smooth and atleast the imbedded portion of the outer surface being roughened.

4. A shoe last comprising a hollow cast body having configured walls ofsubstantially uniform thickness and a top wall spanning the upper end ofsaid body, and a pair of preformed sleeves of a length greater than thethickness of said configured walls, said top wall being cast around saidsleeves to anchor said sleeves in substantially coplanar and parallelrelation spaced from each other and from the configured Walls of saidbody.

CHESTER R. PARKER.

